Train-control system



. 1,619,289 "r. E, CLARK ET AL TRAIN CONTROL SYSTEM March 1, 1927,

Filed April 6, 1925 9 sheets sheet1 INVENTOR-S,

BY M a? 15 m/A mamm 1 4 TTORNE Y.

March 1 1927.

1,619,289 T. E. CLARK ET AL TRAIN CONTROL 'SYSTEM Filed April 6, 1925 9 Sheets-Sheet 2 ATTORNIEY.

March 1 1927.

TRAIN CONTROL SYSTEM Filed April 6. 1925 9 Sheets-Sheet WW QM- l N VENTORS MA A TTORNE? Ill- .NM Ill-v S March 1 1927 v T. E. CLARK ET AL TRAIN CONTROL SYSTEM 9 Sheets-Sheet Filed April 6-, 1925 Q 2 INVENTORS f M BY M 6?.

ATTORNEY.

. l March 1927 T. E. CLARK ET AL TRAIN CONTROL SYSTEM Filed P T 6, 1925 9 Sheets-Sheet 5 INV Rs.

ATTORNEY.

March 1, 1927. 1,619,289

T. E. CLARK ET AL TRAIN CONTROL SYSTEM Filed April '6, 1925 9 Sheets-Sheet 6 INVE-VTORS MM V TTORNEY.

1,619,289 T E CLARK ET AL TRAIN CONTROL S'YSTEM Flled Aprll 6, 1925 9 Sheets-Sheet 7 INVENTORS ATTORNEY.

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M re 1 1927. v 92% a h T. E. CLARK ET AL I TRAIN 'CDNTROL SYSTEM Filed pril 6, 1925 9 Sheets-Sheet 8 S INVENTORS. 'yzfii w A TTORNEY.

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' T. E. CLARK ET AL 'PRAm CONTROL SYSTEM .mamh 1, 192? Filed April 6, 1925 9 Sheets-Sheet 9 .4 TTORNEY.

Patented Mar. 1,. 192?,

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THOMAS E. CLARK AND JAMES CLARK, DETROIT, MICHIGAN, ASSIGNOES TO CONTINUOUS TRAIN CONTROL CORPORATION, 013 DETROIT, MICHIGAN, A GORPORA- TION OF MICHIGAN.

raisin-common SYSTEM.

Application filed April 6, 1925. Serial No. 21,171.

This invention relates to the control oi v railway trains by means of radio or other high-frequency currents propagated in the track rails which are divided into blocks, generators and transmitters of high-frequency currents being provided for each block and being of such character that induced currents may be taken up by proper receiving devices on the locomotive or other i designated vehicle. The object of this inven tion is to provide high-frequency generators and transmitters wh ch Wlll propagate and impress currents of diilerent frequencies 111 hp, er upon the rails of each occupied block,

one'current beingpropagated and impressed when the track is clear for two blocks ahead 1 of the occupied block, another similar current when the second block in advance is occupied, and a third similar current to one of the rails whenever the block in question is occupied, neither the first nor the second current being propagated when the block in advance is occupied, thevinduced current resulting from this third current serving to control devices on the locomotive which will unlock the speed controlling elements and mechanisms governed andcontrolled by the induced currents resulting from the other two currents impressed upon the rails.

39 In carrying out this invention the wires which convey the high-frequency control currents to be propagated and impressed upon, the rails for the purpose of governing and controlling the speed of the locomotive under clearl or caution conditions, are

a} preferably connected to the rails at theexit ends of the several blocks into which the track is divided, or may be divided, and the length of track which will he traveled by 40 these control currents before they'become too weak to produce currents by induction of sufiicient strength to actuate the instr'umem talities on the locomotives, will depend upon the character of the generating and received by the locomotive at separate intervals, during at least a portion of which the control mechanism on the locomotive is unlocked and in condition to be governed by the induced current thus received, the instrumentalities being locked. after such recept on during the time the locomotive is moving to the controlled portion of the next block. I

Gurpresentinvention, which makes use of the track rails as its energy transmitting agents and arranges for such energy to be picked up by induction, might be termed an invisible ram-p system, but it has certain advantages over such ramp and, conductive systems as have been heretofore proposed in that it avoids the serious objections to these systems due to the failures and breakdowns to which they are liable, particularly the failures to transmit currents when their transmitting elements are covered with sleet, ice,' dirt or other insulating materialgand'when the transmitting elements are moved or otherwise disturbed so as to'be out of adjustment and therefore fails to produce proper contacts with the predetermined "parts on the locomotives.

Our present invention is furthermore designed to make use of or to be co-ordinated and used in connection with railroad signal systems of any type, the type shown being of the approach light type, that is,-one in which the signal lights at the exit ends-of the occupied blocks only receive current, and the track wires which supply current to these signal installations are employed to supply current to the control installations. We

have so designed the control'installations vthat no current is transmitted to the rails-0t unoccupied blocks and that should any transmitting installation fail to function, the result will be danger or stopping indica tions within the locomotive cab,

lVe, have further so designed the control mechanism on the locomotive that should the conditions of the track ahead require slacking or stopping of the train, the application of thebrakes by this mechanism will occur 'butwill-he gradual. so as to avoid jolts and jars as far as possible.

Uur invention is pointed out in the hereto annexedclaims and is shown conventionally and diagrammatically fin the; ac

condition of the block cpmpanyingdrawings, in which Fig-1 is a diagram 0 the electric circuits on a vehicle equipped with this novel train control mechanism. Figs. 2 and 2 are diagrarnspf the brake controlling mechanism shown 1n two positions. Fig. 3 is a diagram of a control station. Fi s. 4* to '4 inclusive are diagrams of signal and control installations showing the parts under various track conditions, Figs. 4, 4 and 4 also showing diagrams of the vehicle installation under these conditions. Fig. 5 is a diagram of a track signal installation. Fig. 6 is a diagram of an installation adapted for the end of a controlled track and at the pntrance of a non-controlled track.

Similar reference characters refer to like parts throughout the several views.

We have taken advantage of the fact that the ordinary direct currents employed for actuating and controlling trackway signals'have no effect upon the propa ation of or transmission in the rails of re io highfreguency currents, and that these radio hig -frequency currents have no effect upon the. direct track current or circuits nor an efl'ect upon other radio frequency currents of different wave lengths, so that we use the track rails to simultaneously carry several ofthe radio frequency currents and a direct current. i

The signal system shown in the drawings forms no part of the present invention as a signal s stem, but parts thereof are used as part 0 the train control system, and in order to fully comprehend the control systom, the signal system must be understood. The signal system embodies a multiple-lam stand at the entrance end of each block, eac 1 stand oom rising red, yellow and green Iain S to in icate danger, caution and safety con itions in said blocks; that is, to'indicate that the next, or the second block in advance is occupied or that neither is occupied.

Each block is provided with a track battery at-the entrance end and with a holding relay at the exit end, both connected to the rails, this relay while energized holding up an armature. Whenever a locomotivehF'other vehicle enters the block and electrically connects the rails, and thereby shorts the circuit to the relay, the armature falls and closes, the circuit to a signal lamp at the entrance to the next block in advance, so that the engineer has constantly before him a light indicating the in advance. "The holding relay requires a minimum of. current, much less than is re uired by the light bulbs. The only lights slowing are at the exit ends of occupied blocks. -The character of each light is controlled by the adjacent installation, which, in turn, is influenced h the signal installation of the d? vance. Thus, if a track carry 440 volts A. C., III railway signal systems. Extending from block in a is divided Tinto,

blocks equipped with the installations i lustrated, and the direction of traflic isfrom block A to block D, that is, to the left, and

two blocks ahead of T unoccupied.

Figs. 4* to i inclusive show two wires 1 and 2 connecting lldjflCQ-lllisignal installations. When no current flows over WHOS 1 and 2, as isthc case when train occupies: block D, a red lamp R will be ready to burn at the entrance of block D; plus current flows over wire 2 from installation I) to installation C and back over the wire 1", and a yellow lamp indicating caution will be ready to burn at the entrance of block C; plus current flows over wire 1 from installation C to installation B and back over wire y 2 and a green lightindicating clear will be ready to burn at the entrance of block B. These lights will burn as soon as the blocks leading to them are occupied, but no light is shown unless the block is thus occupied. For the sake of simplicity, the wire 2 will be disregarded and the current over wires 1 and 33 to the polar neutral relay 34 will be considered as plus or minus, as this nomenclature fits the movements of the armature 34*, which swings to the left in the drawings under plus current and to the right under minus current passing to the relay 34.

Each signal installation shown in the drawings comprises two batteries, two neutral relays, one of them the holding relay, and a polar-neutral relay. The energy for both the signal and control systems derived from the wires 3 and 4 which extend along the track and may he considered to .which is often used these wires 3 and 4: are wires 5 and 6 which connect to the fine winding of a transformer 7 which steps down this current to about volts for battery charging. \Vires 8 and 9 lead from the transformer 7 to the rectifier 10 for the track battery 12 to which current is carried by the wires 13 and 14. A second rectifier 15, connected to the wires 8 and 9 by the wires 16 and 17, supplies current to the signal battery 18, wires 19 and 20 0011- necting this battery to the rectifier. These rectiflers may be of any desired construction.

The track battery 12 connects to the rails 21 and 22 by means of sistances 25 and 26 being interposed to protect the track battery from damage when the wires 23 and 24-, the reof the next block in advance.

misses function of track battery is to energize the relay 27 of'the next installation in advance, which holds up certain armatures 27a--b-cd', which armatures en age front contacts to close circuits whic govern the adjacent train control installation; and

also the signaling installation of the next block in the rear. When this relay 27 s deener ized,- its armature J- closes a circuit whic ,-is coinmon to. all the lamps R, Y and G of the adjacent signal Lpost. When, there- 'fore, a block. is occupie the armature of this relay 27 closes one of the circuits to the signal lamps at the exit end of the block, and this results from the short circuiting of the track battery of that block. The particular signal bulb which is to burn is controlled by the wires 1 and 2 and the signal installation A train Tabeing in block D 4*), the relay 27 of that block is deenerg zed and no current flows from the, signal battery 18 to the signal installation at the entrance of block D because the armature 27 has left the 'the track si contact at the end of wire 29 connecting to al wire 2. There is then, no current i t e wires 32 and 33 leading from the tree wires 1 and 2 to the relay 34 of the sig'nalinstallation D at the entrance and of block D. The polar neutral relay 34 of station D, therefore, is not energized and its armature 34 breaks contact with the point I 35 which results in the circuit to the relay 36 being broken andithe 'armaturesj36w,bo

falling to engage their back contacts. When The wire from the bottom of the signal post" 40 is always connected to the battery 18; lhe wire -46 to the red .or danger lamp R 'ends at the back contact engaged by the armature 36 which'is' at one end of the wire 46. The wire 47 extends fromthe armature 36 to the armature 27 which is held up from its back contact so long as the track relay is energized. But as soon as the block G is occu ied, andthe relay 27 is deenergized,

then t is armature will drop, and close the circuit to the wires 48 and 19 to the battery,

causing the danger signal R to become lighted. In other words, the danger signal is ready to become lighted as soon as a train enters block C. v We have now a caution onnegat ve current .in track wire, 1", which flows over the &

wire 33 to the polar neutral relay 34 of sin tion C and back to station D over the wires 32 and 2. The polar armature34 swings.-

counter-clockwise and the neutral armature 34 also. engages the contact 35 at the end of the wire 49 which closes the circuit to the relay 36. Positive current flows from the battery 18' over the wires 20, 37, 38 and 39,

armature 36and wire 30 to the track wire 1 to the signal installation at the entrance of block 4 then back over wire 2 and wire 29, armature 27 wire 42, armature 36", and

wires 43, 4422116. 19 to the battery. This, therefore, is the control circuit ior'thenext indication in the rear.

The circuit for the signal indicationat thisinstallation C is as follows: from the battery 18 over wires 20, 37 and 45, to the signal stand and to the caution yellow lamp Y, thenover 50 to the contact 51, armature 34, wire 52, armature 36*, wire 47 to armature 27. This is, however, held up until a train enters block B and therefore the yellow light does not show until a train shorts the circuit to relay 27 The control current for block ;B .is positive and flows from the battery 18'? over wires 20, 37, 38 and 39, arniature 36, and wires 30 and 1 to polar neutral relay 34 at station B over wire 33 and thence 'to wire 2 over wire 32. The neutralarmature 34 engages the contact 35 on wire 49 as'described inconnec'tion with station C, while 7 the polar armature b engages the contact 54 at the end of wire 55 which connects to the green lamp G on the post 40. 'The, return circuit to thebattery has been described. A

train Tis shown in. block A so 'that relay 27 1 is short circuited and the signal G at station;

B therefore becomes lighted;

The mechanism thus far a train control installation is established which connects to the rails of the block leading to that station and each'control installat1on embodies two transmission devices for i described new. At each signal installation or station llo propagating" radio or other high-frequency currents to the rails, one of the transmission devices generating current of greater free, quency and lesser wave length than the.

other. It is immaterial which of thetwo. is

used for caution and which for clear conditions, so long as the same current is used throughout the entire track for fcaution conditions and the same current for .clear conditions. y r

A pair of wires "and 61. extend the length of each blockand wire 61 connects to the wire 2 of the block in advance by means of a wire '62. Each wire60 connects tothe wire l of the block in advance so long as the relay 27 at the station between these blocks is energized, this connection consisting of the r 'armfiiure 27 and ir 64, as. 1 l

block in advance,

A control installation embodying two. transmitting devices, is installed at the exit end of each block and delivers radio or other high-friupicncy currents of three dif- :t'erent wave lengths, one of the transmitting devices being connected to one of the rails by two wires so that a portion of this rail or zone is in circuit therewith, while the other transmitting device is connected to both track rails, nearer the exit end of the block than the first named device. The first devic is termed the unlocking installation. The second device, termed the control installation. is adapted to impress radio waves of either of two wave lengths upon the rails,

the distance such current will flow along the rails toward the entrance end depending upon the character of the transmitting de vice, but it is desirable to use currents which will be operative at some distance beyond the unlocking zone.

The currents from the unlocking and fromthe control installations in any blo'h depend upon the condition of the second block in advance, and while any desired wave lengths may be employed, 2500 meters. wave length and a frequency of 120,000 has been found to be a suitable current for the unlocking current, 5500 meters and a frequency of 54,600 for the caution current and 6500 meters and a frequency of 40,200 for the clear current. Proper instrumentalities to be described later on are installed upon the locomotives or other suitable vehicles and embody devices influenced by the control currents for determining the speeds of the locomotive under clear and caution conditions. These instrumentalities are unlocked while the locomotive is passing the unlocking zone and respond to the control currents, being locked when the locomotive passes out of the locking zone. The locking zone is preferably about 300 feet long which is also the preferred distance between it and the exit end of the block.

'The unlocking and the control devices operate only when the block to which they are connected is occupied. The train control installation does not operate to transmit current to the rails when the red lamp at the exit end of the block signals danger conditions for the next block, but when the yellow or green lamp at the exit end of the block occupied by the-locomotive signals caution or clear conditions for the next the rails of the occupied block will receive current of either 5500 or 0500 meter wave length.

The several drawings Figs. 3 and 4- to 4 inclusive show two relays 63 and 64, the former a. polar neutral relayhavingarmatures a, I) and c, and the latter a neutral relay having amatures a. and b. The former governs the clear or caution indications and advance.

accurate tuning being provided 100 and 85 the wire therefore a train is speed-control installation and the latter, the locking circuit and the other installation.

Referring nowto Fig. 4?, the control wires and o1 are observed connecting to the wires and 66. The track for at least three blocks in advance is clear so that plus current flows over the Wires 60 and 65 to the relay 63 and over Wires 66 and 61 back'to the next signal installation in The plus current energizes the relay 63' which attracts the armatures a: anfd b'and swing the polar armature c to the le t.

Viires 67 and 68 connect the track power wires 3 and 4 to the primary winding of a transformer 69 and wires 70 and 71 connect to the secondary winding of said transformer and end at the contacts 72 and 73. The normal circuit of the relay 64 is from the signal battery 18 over wires 20, 37, 45 and 7st to relay 6 1 and then back by wire 7 armature 27, wires 76, 31, 48, 44 and 19 to the battery. But the train T is in block D so that the relay 27 is short circuit-ed and therefore does not hold u armature 27, resulting in relay 64; being d e-energized and the relay armatures 64: and 64: engaging the contacts 72 and 73.

The control installations are shown con ventionally in Figs. 4 to 4 inclusive but such an installation is diagrammatically detailed in Fig. 3, the positions of the parts being those assumed when the block, in advance and its own block are unoccupied. \Vhen the block of this control station shown in Fig. 3 is occupied, 110 volts A. C. can rent from the transformer 69 passes over the wires 70 and 71, armatures a and b of the then de-cnergized rela 64, and wires 76 and 77 to the primary 8 ofthe alternating current transformer T9. The secondary 8i of this transformer connects to the plate element 82 of the electron tube 83 by the wire 84, and to-the inductance 86 by wire 85. The winding &1"is shunted by the bypass condenser 87. The wire 88 connects to the inductance 86 and to the grid condenser 89 and grid leak 90, while a Wire 91 completes I the circuit to the grid element :92, the inductance 86 being shunted by a tuning condenser 9.41 An auxiliary winding 95 of the trans former 79 connects to the filament 96 of the electron tube 83 by a wire 97 and to a rheostat 98 by means of a wire 99. A wire 100 connects one side of the filament 96 to a slidable contact 1020a t-he inductance 86,

for by the 103 between the wires 104 forming the connecv'ariable condenser ductance 86'and a 21 while a wire 10? connects this rail to the grid end of the inductance. VVheneve'r in the block controlled by this installation, and-shorts the relay 21 1 plate coil thereof, radio'current will be ind ressed on' the rail 21 between the points i connection of the wires. 106 and 107- therewith. Thisv transmitter functions whenever the block to which it is connected is occupied.

The control transmitter also embodies a transformer 110'having a primary 111, an auxiliary winding 112 and a secondary/113. The primary connects to the contacts 114.- and 115 by means of wires 116 and 117, and thearr'natures 63 and 63 and wires 118 and 119 connect thesecontacts to the armaturcs 64 and 64*. The auxiliary winding 112 commeets to the filament120 of the electron tube- 121 by means of the wires 122 and 123 and the rheostat 124, and the filament is thereby heated.

The secondary 113 connects to the grids element 125 by means of the wire 126, the inductance grid coil 127, grid condenser 128, grid leak .129 and wire 130. It also connects to the plate element 132 by means of the wire 133, variable condenser 134 and wire 135, the

condenser 134 serving to tune this inductance circuit. The secondary 113 is shunted by a-hy-passcondenser 136, and the inductance 137 connects to the wires 133 and 135. A wire 138 connects the wire 135 to the polar armature 63 which engages its back contact .139 when negative current energizes the relay 63, which occurs when .caution conditions are indicated at the adjacent signal installation, and engages its front contact 140 when positive current energizes this relay, which occurs when clear conditionsare indicated at this signal installation. A wire 1421 connects the contact 140 to the wire 133, the variable condenser 143 serving to tune this plate coil 137 to the exact wave lengths desired for clear conditions.

The third inductance coil 144 is connected to the rails 21 and 22 by the wires 145 and 146, the series condenser 147 preventing this inductance from short-circuiting the rails and the track battery 12 at the opposite end of the block.v In Figs. 4 to 4 inclusive, most of the details of the control installations are omitted,- the electron tubes and the inductanccs being indicated by the reference characters of the tubes alone. p

Positive current is passing over the wire (Fig. 4 to the relay63 so that its. armatures a and b are attracted and armature 0 is swung to the left. As track D is occupied at T, track battery 12 is short circuited at tl at point and relays 27 and 6 1 are tie-energized so that an unlocking current passes to the rail 21 over wires 106-407 and a long wave-length or clear currentpasses to the rails 21 and 22 over the wires 145--146.

As the relay 27 is de-energized, its af1na-- ture b breaks the circuit 1 33, 64, 63, 60 so that no current passes over the track Wire so to the relay ca (Fig; 4D) and as relay,

energize relay 63 of station 0 and no control current passes to. rails 21 and 22 The result is that danger conditions revail not only in block D but also in block in (gm distance influenced by the transmitter 12 A negative current flows over wire 1 as previously ex lained and passes over wires 33 and 64 1g. 4) armature 27", wires 63 and 60 to station E and wire 65 to relay 63 which is negatively energized to attract its armatures a and b and swing its armature a away from the contact 140. As track A is occupied at T, relay 64 is-de-energized and v the circuit to transmitter 120 is closed re sulting in short Wave length or caution current being impressed upon rails 21 and The. conditions at station A are similar to those of station I), except that a train T ocwithcupies the next block in the rear and that V therefore thedanger lamp R is giving its signal. Thetrain T in. Fig.4- is therefore receiving both the visual track signal and the cab signal which will loo-explained later on. The engineer of the train '1 (Fig- 4 has been seeing the cleaflsignal G and'has had a clear signal in his cab until he reached the unlockingzone of rail 21, when he received the caution signal in his cab. which he carried all through block 4 until.

he reached the unlocking zone of that block (Fig. 4). At this point he received the danger signal inhis cab just prior to seeing the signal It ahead, and this danger signal indication as he enters block C affects the other instrumentalities on the'locomotive and compels the train to stop. This mechanism will now bedescribed.

I T he retaining apparatus.

- 0n the locomotive, motor car or other 'convenient location is installed a current receiving and brake controlling mechanism whi ai is shown generally in Fig. 1 and on a smaller scale in Figs. 4%43, 4 and 6. This installation comprises four collector loops or co1ls,a tuning condenser and a proper high-frequency relay for each coil, and-three signal lamps to respectively indicate clear, caution and dangei conditions ahead. It also comprises certam neutral relays controlled by the high freing installed in these circuits.

quency relays and armatures for these men tral relays whereby the circuits between a current source and a brake controlling valve may be opened and closed. It further comprises a governor for opening these circuits whenever the speed of the vehicle exceeds that which is permitted for caution or danger conditions.

The fact that the indications in this vehicle installation are fixed at the exit end of each block for the block in advance must be kept in mind. When the vehicle T. Fig. 4: crosses the point. where the wire connects to the rail 2L. one of the collector coils takes up an induced current, and an unlocking neutral relay in the vehicle is energized and its armaturcsclose the circuits necessary to take advantage ot the induced current taken up from between the rails by proper coils on the vehicle and resulting from the currents carried to these rails by the wires H5 and H6.

The several coils which take up the induced currents adjacent to the rails are marked 201, 202. 203 and 204v in Fig. 1. The loop 204 and the high-frequency relay connected thereto are used only when the locomotive passes from a track equipped with this control system to a track not so equipped and will be explained later on. The loops are connected to tuned high-frequency relays 205, 200. 207 and S respectively by means of wires 209, adjustable tuning condensers 211, 2l2 213 and 2l-lbe- Four signal lamps 216. 217, 218 and 210 are -preterably green, yellow, red and white. and indicate clearl, caution, danger and unequipped track way conditions respectively A common wire H connects to these several lamps and to the wire 295 which connects to a normally closed switch 297 (Fig. 2) from which a wire 20S connects to one end of the. battery 293.

This battery may be charged by a. gen orator 285 which connects to the battery by means of wires 280 and 200. and which energizes the core of the magnet 2 7 to draw the switch armature 288' against the contact 280, thus closing the circuit 200 to the battery. Any other desired ineans'may be employed to do this work.

The brake svsten'i embodies a solenoid 302, (Fig. 2) which, when (lo-energized, permits the application of the brakes. but so longas it, is cncr; rized, holds the brake system inoperative. lheret'ore. so long as a. current passes over the wire 296 to this solenoid 308, no automatic application ol' the brakes will occur.

The liigli-ti'eqiie11c v relays 205 to 208 control neutral rela vs 221. 222, 223, and 224 respectively. (of which all but the first are stick-relays) each of which has a three part armature, the parts oi which are lettered 0,

b and c. The high-frequency relay 205 has an armature (z to close the circuit from battery 203, wire 292, wire 225, relay 221, wire 226. armature 205, wires 227, 228, 229, 295, switch 297, and wire 298 to the batter. This causes relay 221 to bring its armature a up to close-the following circuit :-wires 225, 230 and 281, relay 224, wire 232, armature 221 and wires 233, 228, etc., back to the battery. This causes the battery to energize the relay 22 t which lifts its armatures a, b and 0. The train installation is nowiin condition to be positioned for clear, caution or danger conditions in the block ahead. When clear conditions exists, the relay 206 receives current and the armature 206 closes the circuit to the relay 222 which is from the wire 225 over wire 230, armature 224, wire 235, relay 222, wire 236, armature 206 and wire-228 back to the battery via switch 297. The relay 222 then attracts its armatures. This circuit continues until the loop 201 ceases to receive current and the relay 221 becomes de-energizecl and the armature 221 fallsto complete the following circuitz wire 235, relay 222, wire 237, armature 222, wire 238 armature 221' and'wires 233 and 228 to battery via. switch 297. This circuit will continue until the relay 221 is again energized. A portion of the current passing from the battery over wire 235 branches off over armature 222 and thence passes over the wire 239 to green-lamp 216 and back to the battery via switch 297.

The stick relay 224 also receives a. continuous current from wires 225, 230 and 231 which flows over wire 241, armature 224. wire 242. armature 208*, to wire 229 and back to the batter via. switch 297. When the. relays 222 am .224 are thus energized, current flows from tire wire 235, armature 222, wires 243 and 244, armature 224 and wire 296 to the solenoid 308 which will he therefore energized whenever hoth relays 221 and 222 are energized. The high-frequency relay 206 receives current at the. exit end of the blockonly and is thcre'tore de-energized most of the time, its

neutral relay 222 beiug kept energized by the current that passes from the wire 235, relay 222, wire 237, armature 222". wire 238, armature 221 and wires 223 and 228 to the battery via switch 297. Whenever there fore this relay 221 is again energized at the exit end of the next block. it releases the relay 222. The parts are therefore in condition to receive control from the current received over the wires 145-446 at that exit end.

. cirlpuit from the wire 235 overwire 2465, re- 1a p223, wire 247 to wires 228 and 229, ca11sing the: relay 223 to beenergized to draw its armature against the contact at the end of Wl1e248, and at the instant the relay 221 is de ehergized the following, circuit is pro-' duced' from wire 235 over wire 246, relay 223, w1r e 2l8, armature 223, wire 2&9, armature 221 and wires 233 and 228 back to the battery vie switch 297.

This'ak eeps the relay 223 energized until the unlocki g circuit-again functions, but

whilefit is energized current flows over wire 235, armature 222*, wire 250, armature 223 and wire 252 to the yellow lamp 217. Cur

rent also flows over wire 235, armature 222, wire 253, armature 223, wire 254C to the movable contact 255 of the governor 256'which may be constructed as shown incur prior epplication, Ser. No. 719,002, filed June9, 192%.. p In this construction, contact 255 roamains in engagement with the contact 257 until the locomotive exceeds a. predetermined speed, say 20 miles er hour, and if it ,exceeds this speed, will swing out of contact, as shown in Fig. 1. From contact 257 current flows over wires 258 and 244, armature no current is recelved by either loop 202 or 224: and wire 296- tosolenoid 308. So long therefore as the train does not exceed the predetermined speed and Ciilll310l170011d1- tions existin this control installation, current flows to solenoid 308.' The governor 256 has a second movable contact 260 which controls the speed permissibleunder danger conditions, say four miles per hour, at which speed this contact 260 disengages the contact 257. But at lowerspceds these contacts remain in" engagement.

As stated before, thereley 221 is energized at the exit end of each blockand the relay 22 1 is always energized at the same time.

203, danger conditions exist in the next block ahead and the relays 222 and 223 are tie-energized. Current flows from wire 235 over armature 222, wire 253, armature 223,

wir'e 262, armature 221 and wire 263 to, the

movable contact 260, and while. the speed of the train is notgreater than that predetermi'ne'd for danger conditions, the current flows from contact 257 over wires 258 and'2 t4, armature 224 and wire 226 to sole- (lil noid 308.

We have therefore an installation adapted to take. up three induced high-frequency currents of different wave lengths, one to cause the unlocking of the neutral relays and their ermatures, a second toinfluence the cantion relay, and the thirdto influence the clear relay. An absence of both the two latter currents influences the )arts to assume danger positions. When t epartsvarein clear positions, the solenoid 308 is always energized. When in caution positions this solenoid is energized so long asthe two conis shown in Fig. 6 may be connected to j tects 255 and'257 o t the speed goveriior engage; and when in danger positions, this solenoid is energized solong as the two contacts 260 end- 257 enga e. I When a. portion 0 the track is not equipped with the train control app above described, a track installation sec exit end of the last controlled block. 270 and 271 connect the transformer the wayside wires 273 an 274 connect this trztnsformer to the transmitter 2751 of high-'l'reqnency current of e different wave length than that; of any of the currents transmitted over the wires 106107 or 145-146. Armetures ower wires 3* and 4 white the and b ofthe relay 276 control the circuits of I this transformer and this relay is controlled by the track relay 27 as follows?- So long as this block is unoccupied, this i i relay 27 is energized by the track battery 12 at the next installation in the rear but when the train T short circuits this rel comes de-ener 'ized and its armetures a, 5

end 0 drop to isengage their front contacts.

The relay 276 is normally energized by a. current flowing from the battery 18 over wires 37, 45 and 277 tothis relay and over wire 27 8, armature 27", wires 31, 44 and 19 back to the battery. But when the relay 27 is de-energized, this circuit is broken and the armatures 276 and 276 close the circuit be tween the transformer 272' and transmitter 275 and this results in high-frequency current flowing to the rail 22 over the wires 280 ay, it be I Ice and 281, so that an induced field is just above the section of the rail between these wires 'where it may affect the collector coil 20% .whose condenser 214 is properl the waive length'of this induced eld. When It this occurs mange- 1,208 (Figs. 1 end 6) permits its srmatureia; to break the stick circuit to relay 224 which permits its ermatnres b and a to engege their back contacts. The

circuits which are closed thereby ere from the battery-293 over wires 225 and 230 to the contact 282, armature '22 Qand wire 296 to the solenoid 308. Current also flows from tuned for the wire 230 over. armature 22s, and wire T he broke iristallatioqu The brake installation shown in. Figs. 2

and 2 is adapted to be connected to the ordinary air brake systems now in use.

These embody the main" air reservoir 303, the equalizing reservoir 30 1, the engineers brake valve 305, the pipe 306 connecting the main reservoir to the brake valve, the pipe 307 connecting the equalizing reservoir to the brake valve and the train pipe 318. It may be said that the train pipe 318 is filled with air under properpressure to prevent the application of the brakes and that this pressure is, as a rule, gradually released by manipulating the valve 205 in order that the brakes may be applied gradually. hen the brakes are to be released the engineer brings this valve to proper position to again charge the train pipe from the reservoir 303. In the present installation, means are provided tor a preliminary partial ap 'ilication of the brakes and a subsequent final application. both being entirely out of the control o t' the engineer.

The S\\'ltill 207 is placed between the wires 1308 and 206 and this switch is kept closed by air pressure below the piston 306 Within the cylinder 301, this pressure being supplied by the pipe 3J2 connecting to the pipe 366. So long, therefore, as pressure exists in the main reservoir 303, this switch is kept closed, but when the locomotive is in the round house or dead, this switch is open and thus prevents themain battery 293 be ing discharged.

As stated before, current passes over the wire 206 to the solenoid 308 so long as the locomotive not exceeding the proper speed. When this occurs. the circuit to the solenoid is opened and as the solenoid becomes deenergized its armature 309 falls and the valve 310 leaves its position in Fig. 2 and moves to that of Fig. 2". When this occurs, air flows from the pipe 306- through pipe 202- to valve body 311 and through pipes 312 and 313 to the cylinders 31st and 315. The piston 316 in cylinder 314 is connected to the valve 31.7 which moves to close the passage from train pipe 318 to the valve 305, thus preventing the engineer from to charging the train pipewhile the solenoid 308 is (lo-energized. but it does not prevent him from discharging this train pipe 'tl1is being permitted by the check valve 310.

Attention is called to the valve body 320 in which a valve 321 is slidable. pipe 318 normally connects to this valve body through the pipe 322 so that train pipe pressure is bad in each of the three small t lllil'fil re ervoirs 323. 324 and 325. and by reason ol the pipes 326, 327 and 328, this pressure is had in the upper part of the equalizing valve 329, both parts o'f'the di=1- phragm valves 330 and 331 and in thc'upper part of: the relief valve 332.

When the. pressure in the cylinder 315 move the pis on 331 to the right. the end 335 of valve 321 closes the ports to the pipes 322, 327 a ud 328, thus preventing recharging out).

The train of the small control reservoirs 323. 32 i and At the same time, the port 336 in the valve 321 is moved out of alinement with the pipe 337 leading to the valve 332, but

the port 338 in this valve 321 has been moved to connect the pipe 337 to the calibrated discharge pipe 339. So also the port 3-1-0 has been moved to connect the pipe 342 to the pipe 343 leading to the cylinder 3-14, the pipe 342 having formerly been closed by the valve 321 and the pipe 343 being formerly vented by this port 3&0 and the discharge opeming 3 15. I

When tlivalve 321 moves to the position shown in Fig. 2, air will rush from the top of the valve 331 through pipe 312, port 3 1-0 and pipe 343 to cylinder 34st and push up the piston 346 to lift the switch 347 to open the circuit to the now de-energized solenoid 308, thus preventing the circuit to this soleiioid being closed. x

A diaphragm 3 18 in the valve body 330 carries a stem 349 and a valve 350 is attached to the upper end thereof. A disk 351 on the lower endot' this stem engages the spring 352 which normally holds the valve 350.from.its seat, the pressure above and below the diaphragm 348 being normally equal because of the pipes 326 and 353. Similarly. the diaphragm in the valve body 331 carries astem 355,]valve 356, disk 357 and spring358. The diaphragm 359 in valve body 332 carries a valve 360 which closes an opening controlled by a needle valve 361. As this valve is vented at 362, the valve 360 is normally held 'on its seat by the pressure above the diaphragm and thus prevents flow of air from the control reservoir 325 through the .pipe 363.

When the valve 321 is in the position shown in Fig. 2, air flows from the upper parts of the valve bodies 330, 331 and 332, which are connected by the pipes 364 and 365, through the pipe 337, port 338 and vent Air also flows from the upper part of valve body 329 through pipe 366 to the valve body320, and through pipe 326 and valve body 330 to the pipe 337. The pressure above the piston 367 is therefore reduced, permitting the pressure below this piston. that is, train pipe pressure, to lift the valve 368 from its seat so as to permit a portion of the train line pressure to escape at 369, which results in a partial applicatioi of the brakes.

The pressure above the diaphragm 348 is, however, not sutliciently reduced to permit. the pressure in reservoir 32st to overcome the force of the spring 352 which holds the valve 350 off its seat. The pressure in the upper part of the valve body 331 slowly reduces by reason of the pipe 365 so that the excess of pressure below the diaphragm received from the partial reduction reservoir 325 system embodying a. train control valve and electromechanical means to hold it closed. a current source and circuits between it and said valve, collector coils and relays connected thereto resjmnsive to l'iigh-l'requen y currents in the rails to hold losed a plurality'ot' said circuits according to the currents received by said coils, and an additional collecttn coil and a relay connected thereto. which. when responding to a selected high-frequency current, is adapted to render said first named coil and relays inoperative and close another of s2fid circuits hctwcen the current source afiil alve Select the wave length of the current propagated by a control station.

1.). ln :1 train control s 'stenn the coinlllllatltlll of a normally energized hrake control apparatus two cilctlltQ corrcspoml ing to ditlerent pcrmixwilile speeds for the vehicle and each effective to mainta'w said hrake control device energized. speed-responsive means governed by the actual speed of the vehicle to open either or" said circuits. a ollector coil for each of said circuits and mounted on the vehicle adjacent the trackway to receive high-frequency current of a predetermined wave length. means connected ll. In an automatic train control systcinieto each coil and atlected hy the current taken the couihination of a track diridcd into ltlttl'lif. a control lnstallatlon to propagate higrh-l'rer ncncy current of dlflercnt wave lcngtlh in the rails of each hloclt. a signal in tallation cinhodying lamps of ditlcrcnt colors at one end of each hlock. means, in

clluliugr wires extending hctwccn adjacent; Hlfjlhtl lnatullationst ntrolled h v the presence or aliecnce of a clnclc 1n the three l lUK'hS in advance to sele t the Signal lamp.'

and means. including wires extending hetween adjacent control installations, controlled hy the presence or absence of a vehicle in the three blocks in advance to up thereby to open and close one of said circuits. :1 third collector coil mounted on the vehicle adjacent the trackway to receive high-frequency current of another wave length, and means connected to said last named coil adapted to render operative the first; named collector coils and the means connected thereto while Silltl last named coil receives current and to prevent. change in said circuite to the brake control device when no current is received by said last named coil.

THOMAS E. J'LARK. JAMES E. CLARK. 

